Even the most ardent firearm lovers admit that Smith & Wesson's new . 50-caliber Magnum revolver is more gun than anyone needs.

It has double the power of most assault rifles in America. Its kick can send a grown man reeling, while a single bullet can drop a grizzly bear. It is so heavy and long that police say no criminal would dare try to hide it in his waistband. It will cost as much as $989.

And gun buyers across the United States can't wait to get their hands on it.

"The initial reaction has been even stronger than we had anticipated, so we're ramping up production to meet the demand," Bob Scott, Smith & Wesson Corp. chairman, said from the 2003 Shooting, Hunting, Outdoor Trade Show in Orlando, Fla.

The Springfield, Mass.-based company, creators of the .44 Magnum of Dirty Harry fame, unveiled its new offering Thursday as the world's most powerful commercially produced revolver. Executives for the country's second-largest firearms manufacturer said they hoped the gun would help regain lost market share by generating excitement among an important -- albeit "niche" -- market of big-game hunters, collectors and recreational target-shooters.

"We see this as an opportunity for backpackers," President Roy Cuny said. "A light firearm of this caliber, in fact, provides protection against bears and other big things."

But even before the gun's wide distribution, scheduled for next month, anti- gun forces are taking aim at its social impact.

"A hunting weapon? That's a joke," said Luis Tolley, director of state legislation for the Brady Campaign to Prevent Gun Violence. "What we have here is a weapon that's designed to appeal to people who just want to make a bigger hole in whatever they're shooting at, and hopefully they're not living next door to me."

Smith & Wesson has built its reputation by building bigger guns. The new Model 500 uses a bigger frame than all others, takes a new .50-caliber Smith & Wesson bullet and packs a muzzle force of 2,600 foot-pounds. While there are single-shot, custom pistols that use larger ammunition, the new gun is the largest production firearm with a multi-bullet chamber.

At .50 caliber, the bullet is about a half-inch wide but is more powerful than other such ammunition because it is longer and can pack more powder, said Garen Wintemute, a gun expert and director of the Violence Prevention Research Program at UC Davis.

He predicted it would be a smash with gun enthusiasts, who can order one with a barrel as long as 10 inches.